Laidlaw's B&I Lions dream shattered?
The Gloucester scrumhalf, capped 58 times, had to go off during the first half of Scotland's 16-22 loss to France in Paris last Sunday and a subsequent scan revealed he had sustained ligament damage.
"Scotland captain Greig Laidlaw has been ruled out of the remainder of the 2017 RBS 6 Nations with an ankle injury," the Scottish Rugby Union said in a statement.
"Laidlaw will see a specialist later in the week to determine the best course of management and estimated time out of the sport."
The injury means his dream of travelling with the British and Irish Lions to New Zealand in June may well be over.
Laidlaw, 31, started the tournament in style, kicking two late penalties to give Scotland a thrilling 27-22 victory over Ireland in their opening match.
But he spent just 24 minutes on the field against France and left the Stade de France on crutches before returning to Gloucester on Monday to be assessed by the club's medics.
The injury robs head coach Vern Cotter of both Laidlaw's leadership skills and his abilities as a kicker.
Glasgow's Ali Price came on for Laidlaw in Paris and is expected to retain the number nine jersey when Scotland welcome Wales to Murrayfield in their next game a week on Saturday.
Scarlets flank John Barclay took over as captain against France, but was then forced off by a head injury.
It leaves Glasgow co-captain Jonny Gray as the most likely candidate to skipper Cotter's men against the Welsh.
